Relay-telephone



(No Model.) V

H. O. STRONG.- Reley Telephones.

No. 235,658. Patented Dec. 21,1880.

UNTTEE STATES PATENT @EETEE.

HENRY o'. STRONG, or onIoAeo, ILLINOIS.

RELAY-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 235,658, dated December21, 1880.

Application filed May 10, 1880. (No model.)

To all whom it may concern:

Be it known that I, HENRY O. STRONG, of the city of Chicago, and countyof Cook, and State of Illinois, have invented certain new and usefulImprovements in Relay-Telephones 5 and I hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanying drawings, forming part of thisspecification andI designate my invention an improved. telephone withrelay attachments, the telephonemagnet being securely attached totelegraphrelay cores when used on long circuits.

My invention consists, first, of a metal tube, in which is inserted,through a socket or opening in the lower portion, a beveled bar-mag net,to which is attached a spool of insulated wire, the same as used intelegraph-instruments. The magnet and spool thus combined adjust or turnwithin the tube below, but not touching the diaphragm of non-conductingsubstance, to which is attached a soft-iron disk, just above the magnet,as large as the end of the magnet beneath it. Above thisnonconductingdiaphragm I place a secondary diaphragm. with a perforationin the center thereof, and, just above the soft-iron disk, attached tothe non-conducting diaphragm. By this combination of diaphragms apeculiar augmented magnetic effect is produced in thereceiving-telephone, neutralizing induction and magnifying the tones ofthe human voice when received from the speaker at the remote end of thecircuit, in nowise diminished by the length of the circuit or the hightension of the electric current of the telephonic closed circuit.

My invention consists, second, of a spool or coil of insulated wireattached to the lower or opposite end or pole of the magnet and fastened by a nut on the end of the magnet, the thread of which engages withthe thread cut on the end of the magnet, holding both spools on thebeveled magnet firmly in their place, the beveled form of the magnetproducing an increased magnetism within the iron tube, for the-reasonthat there is alarger amount of metal at the end next the diaphragm, andconseqaently greater attraction and repulsion than there would he werethe magnet of the same size throughout its length. Thus securelyattacheththe additional coil at the lower end of larity of the magnet,making communication distinct and reliable on long circuits, andlessening the induction. The ground-plates, arranged as describedherein, may be connected, as shown in the drawing in Letters Patent No.192,856, granted to S. J. M. Bear on 10th of July, 1877, or in anysuitable mannerby which the electric earth-current may be generated andtransmitted to the coil of the relay on the lower end of the magnet.

Figure l is a sectional "iew of the telephone, showing the beveledmagnet in elevation. Fig. 2 is an inverted plan of the non-conductingdiaphragm having the metal disk attached 9 and Fig. 3 is a plan of theperforated metallic diaphragm.

Referring by letter to the drawings,A designates the beveled magnet,having the spool B at one end and the spool O at the other end.

D designates the iron tube, threaded upon its exterior and encased invulcanized rubber F.

E is vulcanized rubber surrounding the magnet A within the tube D.

G designates a metal cup which screws up on the iron tube D.

H is the wooden cap or mouth-piece which screws upon the cup G and holdsthe diaphragms I and J in place above the enlarged end of the beveledmagnet A.

K designates the metal disk attached to the paper diaphragm J, whichlatter has a ring, J, which rests upon the cup G.

I designates the perforation in the diaphragm I.

By screwing the cup Gr upon the tube D the diaphragms maybe adjustednearer to or farther from the end of the magnet A.

land 2 designate the battery-wires, and 3 3 the line-wires.

L is the head of the telephone, to whichthe posts are secured. I) is asecuring-nut on the threads at.

1 do not limit myself to any particular mode of construction of the irontubes for my telephones, but make use of iron tubes in order to complywith magnetic radiations affecting soft iron, which becomes magnetizedwhen placed near a permanent magnet, and becomes demagnetized on being\vithdrawnfrom the presence of the magnet. The iron tube, not being apermanent magnet, has an attractive influence for the end of the beveledpermanent magnet, and increases the polar attraction therein when thetelephone is in circuit. I thus duplicate the diaphragms, and place themnear, but not in contact with, the end of the beveled magnet within theiron tube, and the magnetisms pervading the metal in the doublediaphragms and iron tubes react on each other while in the presence ofthe beveled magnet, such magnetic reaction producing distinct articulation in the telephone through which the' communication is beingreceived, allaying the induction so common in speakingtelephones in use.

I have found by actual experiment with a telephone constructed as hereindescribed and shown, that induction is allayed so as to be unheard, or,at most, heard only very faintly.

What I claim as new, as my invention, and desire to secure LettersPatent for, is-' 1. In a telephone, the beveled bar-magnet A, carryingthe spools B and G, in combination with the iron tube D, casingE and F,and the double diaphragm I I J K, constructed and operatingsubstantially as and for the purposes set forth.

2. In a telephone, the'combination, with the magnet A, spools B and Oand tube D, and casings E F, of the adjusting-cup G, carrying the doublediaphragms I J, substantially as and for the purposes set forth.

3. In a telephone, the beveled bar-magnet, in combination with thespools B and O, and the securing-nut b, as set forth.

HENRY O. STRONG.

Witnesses:

J. T. SoLoMon, CHARLES W. BITTER.

